I believe I have the same problem. Everytime I swollow it is there. I have to force a cough and even then it doesn't come up. I also have "smelly snot" it's disghusting. Going to see my GP tmz. Will let you know how I get on. But it does sound like what you've been discribing. The mucus effects m through and nose. Chest seems fine. Shortness of breath only occurs if I laugh to hard.